Contradictory Results

We studied prevalence of dementia in 1642 subjects aged 75-101 and found that those with relatively low blood pressure (lower or equal 140 mm Hg systolic, lower or equal 75 mm Hg diastolic) were significantly more likely to have dementia.

source:Low blood pressure and dementia in elderly people: the Kungsholmen project, BMJ 1996;312:805-808 (30 March); http://www.bmj.com/cgi/content/abstract/312/7034/805



We conclude that AD patients have mildly impaired autonomic functions, mainly in vagal parasympathetic functions. The pathogenesis and clinical significance of low blood pressure in AD needs further study.

source: Cardiovascular Autonomic Functions in Alzheimer's Disease, 1994
http://ageing.oxfordjournals.org






Conclusions A history of hypertension is related to a higher risk of Mild Cognitive Impairment. The association seems to be stronger with the nonamnestic than the amnestic type of MCI in the elderly. These findings suggest that prevention and treatment of hypertension may have an important impact in lowering the risk of cognitive impairment.

source:Hypertension and the Risk of Mild Cognitive Impairment, http://archneur.ama-assn.org/cgi/content/abstract/64/12/1734




We cross-sectionally assessed the relation between S. Blood Pressure and cognition in a cohort extending from mid- to late-life……….Thus, even in the normotensive range increasing systolic blood pressure is inversely related to cognition.

source: High-Normal Blood Pressure Is Associated With Poor Cognitive Performance, http://hyper.ahajournals.org/cgi/content/abstract/51/3/663



Increasing age, fewer years of education, and the apolipoprotein E 4 allele were significantly associated with increased risk of Alzheimer’s disease. Use of nonsteroidal anti-inflammatory drugs, wine consumption, coffee consumption, and regular physical activity were associated with a reduced risk of Alzheimer’s disease. No statistically significant association was found for family history of dementia, sex, history of depression, estrogen replacement therapy, head trauma, antiperspirant or antacid use, smoking, high blood pressure, heart disease, or stroke.

source: Risk Factors for Alzheimer’s Disease: A Prospective Analysis from the Canadian Study of Health and Aging, American Journal of Epidemiology, Am J Epidemiol 2002; 156:445-453. http://aje.oxfordjournals.org


Nonlinear Relations of Blood Pressure to Cognitive Function

Cross-sectional findings, across testing sessions, indicated moderated U- and J-shaped relations between BP and cognitive function. Both high and low diastolic BP were associated with poorer performance on tests of executive function and confrontation naming among less-educated persons; with tests of perceptuo-motor speed and confrontation naming among nonmedicated (antihypertensives) individuals; and with executive function among older individuals. Cross-sectional linear relations included higher systolic BP and poorer nonverbal memory in nondrinkers, and higher diastolic BP and poorer working memory among less-educated individuals. Results indicate that cross-sectional and longitudinal relations of BP to cognitive function are predominantly nonlinear and moderated by age, education, and antihypertensive medications. Careful monitoring and treatment of both high and low BP levels may be critical to the preservation of cognitive function.

Source: American Journal of Hypertension, (Hypertension. 2005;45:374.)
http://hyper.ahajournals.org/cgi/content/full/45/3/374